相等的codeigniter查询生成器数据库错误

Question

我在将 SQL 语句转换为 CodeIgniter 查询生成器记录时遇到问题。在工作台中，我运行以下查询没有问题。

这适用于 MySQL WorkBench...

# This 
SELECT DISTINCT
    projects.id, projects.title
FROM
    projects
INNER JOIN
    positions
ON
    (projects.id = positions.project_id)
WHERE (positions.is_draft = '0')

查询生成器

$this->db->select('DISTINCT projects.id, projects.title');
$this->db->from('projects');
$this->db->join('positions', 'projects.id = positions.project_id', 'inner');
$this->db->where('positions.is_draft', '0');
$query = $this->db->get();

return $query->result(); 

错误

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.`id`, `projects`.`title` FROM `projects` INNER JOIN `positions` ON `projects`.`' at line 1

SELECT `DISTINCT` `projects`.`id`, `projects`.`title` FROM `projects` INNER JOIN `positions` ON `projects`.`id` = `positions`.`project_id` WHERE `positions`.`is_draft` =0

我也试过了

$this->db->where('positions.is_draft = 0');

我认为问题在于 equals 分配，但你怎么看？我玩过它，但总是遇到同样的错误。

Answer 1

可能与 distinct() 有关。在 Codigniter 中有多种使用 distinct 的方法。

$this->db->distinct();

或者在你的例子中试试这个

$this->db->select('DISTINCT(projects.id), projects.title');